17 research outputs found
Bases for Integer Generalized Splines on Graphs, an Investigation
No full textv, 20 p.Let R be a ring and G a graph whose edges are labeled by ideals of R. A vertex labeling of G by elements of the ring is called a generalized spline if for each edge, the difference of the labels of the two connected vertices lies in the edge's ideal. The author examines the algebraic structure of the set of generalized splines -it is actually an R-module- and present results of Handschy, Melnick and Reinders concerning the existence of splines where the graph is a cycle and the ring is Z. The author also summarizes more general results of Gilbert, Polster and Tymoczcko regarding existence of nontrivial splines on arbitrary graphs. They show that when working over an integral domain, the set of all splines on a graph contains a free submodule whose rank is the number of vertices. The author gives examples of their construction working over the ring of integers
An examination of constraints on fruit production by smallholder farmers in Vhembe District
No full textMRDVInstitute for Rural DevelopmentThe production of fruit commodity is crucial for livelihood, job creation and income generation. Smallholder fruit farming has become one of the key strategies to tackle the problems relating to health, lack of employment and poverty amongst rural people. The purpose of this study was to investigate fruit production levels by smallholder farmers in the Vhembe District of Limpopo Province, with special focus on mango, avocado, and macadamia nuts. The author investigated factors affecting smallholder fruit farmer's productivity and suggested policy recommendations that could lead to enhanced production. The author used both quantitative and qualitative methods of data collection by interviewing smallholder fruit farmers, and officials dealing with fruit production using structured and unstructured administered questionnaires in making observations of their farming practices. Out of a total population of 439 fruit producers, 224 were selected by employing the stratified random sampling procedures in Thulamela, Makhado and Mutale local municipalities in Vhembe District. The Statistical Package for Social Sciences (SPSS 2012, 20) was used to capture and analyse data. This was done to draw frequencies and cross tabulations. Content analysis, frequency distribution, and descriptive statistics were used to answer the objectives of the study. The study revealed shortage of water, low input use, lack of storage facilities, inadequate access to land, insecure tenure, insufficient pests, insects and diseases control, lack of access roads, labour, communication infrastructure and lack of practical management skills as major constrains contributing to low fruit production. It was envisaged that the results of the research would provide compelling scientific information that would help create a better platform for implementing improved farming strategies by government
Genre Analysis of Move Structures in Job Interviews by the Judicial Service Commission of Kenya in 2011
No full textMany scholars have carried out research on genre analysis (Swales, 1990, Bhatia,1993, Bruce, 1993), Flowerdew, 2002, Fairclough,, 2006, and others) and their findings have opened many avenues for research and analysis of many genres. However, much of their studies have scarcely attempted to analyze move structures of job interviews conducted by a judicial commission in any country. A literature gap therefore exists, thus motivating the authors to analyze the move structures of JSC’s interviews using Genre analysis theory. A genre analysis involves a survey of certain aspects, including : the identification of communication purposes and overall schematic structure of the target text, the analysis of lexico-grammatical features which involves quantitative corpus studies, the analysis of text patterning, which includes the analysis of conventionalized patterns of language use at lexical, syntactic and discourse levels and lastly, the analysis of content-based organization, conventionally described as substance specific moves (Swales, 1990). A move is a unit that incorporates both purposes and content that the writer intentionally communicates to the reader (Bhatia, 1993). The present study aimed at investigating how the move structures of job interviews conducted by the Judicial Service Commission of Kenya in 2011 correspond to the interview process models as designed by Huffcut & Roth (1998), Adelsward (1998) and other scholars. Through a genre analysis of interviews texts extracted from the interviews conducted by the Judicial Service Commission of Kenya, the present study is aimed at exploring the moves employed in the interviews for certain communicative purposes. The results of the study indicate that the JSC interviews make use of certain moves that are usually textually realized through certain linguistic forms. The study has identified some linguistic realizations that are used to develop the moves of job interviews and it has attempted to offer solution to some language challenges that emerge in the process of using language as a tool to address some problems in our society. Keywords: Genre analysis, communication purposes, interviews, overall schematic structure, lexico-grammatical features
THE OBJECT OF LOVE IS FOOD Conceptual Metaphor in Selected Dholuo Benga Music of 1970s and 2000s
No full textAn Analysis of Speech Acts in Margaret Ogola's the River and the Source and I Swear by Apollo
No full textNovels are characterized by narration. However, in some instances depending on the style of the author, some portions of the novel may consist of interactions between the characters. It is therefore through speech acts analysis that the reader can interrogate how the writer develops the plot, characterization and the major concerns in the novel through discourse situations where a character talks to another character. This study examined speech acts in Margaret Ogola's two novels' The River and the Source (1994) and I Swear by Apollo (2002).In this regard, the objectives of this study were, firstly, to interrogate the significance of speech acts in comprehending dialogue in the novels The River and the Source and I Swear by Apollo, secondly, to describe the types of speech acts used by the writer in the novels The River and the Source and I Swear by Apollo, and finally to evaluate the uses and significance of speech acts used in the novels The River and the Source and I Swear by Apollo. Austin's (1962) Speech Act Theory guided this study. The study employed an analytical research design. A mixed method approach was used to analyze the data. Qualitative method was used to present the data in form of description whereas quantitative was used to count the total number of the speech acts used by the main characters. The population in this study was all the four novels by Ogola. To achieve its objectives; the study purposively selected two of her four novels due to the extensive use of dialogue in these two novels. Library research and content analysis were used in collecting data. Data was obtained from reading and analysis of the primary texts supplemented by secondary texts. The data was in form of utterances from the characters' conversations containing speech acts. The study concluded that speech acts in pragmatics could be used in the analysis of characters' utterances in the novels in the same way as daily verbal interactions. Secondly, the findings indicated that every utterance used by a character performs three simultaneous acts, namely: a locutionary, an illocutionary and perlocutionary. Moreover, every utterance produced by a character in the novels could be categorized under one of the five major categories of speech acts proposed by Searle: representatives, expressives, directives, commissives or declarations. The study found that all these five major speech acts were used by the writer in the novels with the representative being the most dominant in both novels and the declarations the least. In addition, the successful performance of each speech act depends on satisfying the four linguistic and non linguistic conditions called felicity conditions which interlocutors use in production and interpretation of utterances. These are the propositional, preparatory, sincerity and essential conditions. The study also revealed that each major speech act contains a wide range of sub acts or illocutionary forces which are distinguished based on their felicity conditions. For this reason, the findings showed that the writer used thirty six sub acts in the novels with the act of asserting having the highest frequency. Finally, the study also found out that both direct and indirect speech acts are used in the novels with the direct speech acts having the highest frequency of use. This study recommends that a speech act analysis be adopted as an effective tool in the analysis of the characters' verbal interactions in novels. In addition, it recommends that further research be conducted on speech act analysis of novels by other writers
Water Flow Behavior and Storage Potential of the Semi-Arid Ephemeral River System in the Mara Basin of Kenya
No full textAlluvial corridors of ephemeral river systems provide viable opportunities for natural water storage in dry lands. Whilst alluvial corridors are widely recognized as water buffers, particularly for areas experiencing constant water scarcity, little research has been undertaken in Sub-Saharan Africa to explore their hydrological variability and water resource potential as alternative water sources for nearby communities. This study investigated the water flow behavior and storage potential of an ephemeral river system in the Mara Basin of Kenya for purposes of supporting water resources development and ecological sustainability. The water flow processes – including the recharge rates and water loss processes – from existing sand storage systems were established through monitoring of ground and surface water levels. Water samples along the alluvial corridor were collected and analyzed for major ions and isotopic signatures required to establish the water storage dynamics. The storage potential was estimated through Probing and Electrical Resistivity Tomography techniques, augmented with in-situ measurements of hydraulic conductivities and channel bed porosities. The mean annual storage volume in the alluvium of the study reach was estimated at 1.1 Mm3, potentially capable of providing for the annual domestic and livestock water demands of the area. Transmission losses into the alluvium beneath the ephemeral channel-bed were noted to attenuate the flood peak discharges, depending on the level of saturation of the alluvial bed. However, water storage in the alluvium was subject to losses through evapotranspiration and seepage through fractured bedrocks. The study demonstrated the potential of alluvial corridors as water storage buffers providing alternative water sources to communities within the dry land regions with water scarcity, thereby to supporting ecosystem sustainability.Water Resource
Fever and its treatment among the more and less poor in Sub-Saharan Africa
No full textThe author empirically explores the relationship between household poverty and the incidence and treatment of fever--as an indicator of malaria--among children in Sub-Saharan Africa. He uses household Demographic and Health Survey data collected in the 1990s from 22 countriesin which malaria is prevalent. The analysis reveals a positive, but weak, association between reported fever and poverty. The geographic association becomes insignificant, however, after controlling for the mother's education. There is some evidence that higher levels of wealth in other households in the cluster in which the household lives are associated with lower levels of reported fever in Eastern and Southern Africa. Poverty and the type of care sought for an episode of fever are significantly associated: wealthier households are substantially more likely to seek care in the modern health sector. In Central and Western Africa those from richer households are more likely to seek care from all types of sources: government hospitals, lower-level public facilities such as health clinics, as well as private sources. In Eastern and Southern Africa the rich are primarily more likely to seek care from private facilities. In both regions there is substantial use of private facilities--use that increases with wealth. Like the incidence of fever, treatment-seeking behavior is strongly associated with the level of wealth in the cluster in which the child lives.Disease Control&Prevention,Health Systems Development&Reform,Public Health Promotion,Health Monitoring&Evaluation,Early Child and Children's Health,Health Monitoring&Evaluation,Poverty Assessment,Communicable Diseases,Statistical&Mathematical Sciences,Health Indicators
Author Correction: Spatial analysis and risk mapping of Crimean-Congo hemorrhagic fever (CCHF) in Sub-Saharan Africa
No full textAn analysis of building behaviour of the termite Macrotermes subhyalinus (Rambur)
No full textAlthough the work presented in this study is little more than a first survey of the causal factors involved in construction behaviour of Macrotermessubhyalinus , it clearly indicates a fertile field of research which has scarcely been explored. Past studies have concentrated on the release of building behaviour and have done little (with the exception of Grassé, 1959) to account for the formation of the various types of structural elements present in termite nests. The present study gives a general account of building behaviour and of the formation of several structural elements: volatile chemical cues in concerted action with tactile stimuli provided by physical objects, cause workers to grasp soil pellets, transport them, and subsequently deposit them at a building site. The ability of termite workers to employ pheromones in a versatile way in their orientation is the underlying condition which gives rise to the formation of a variety of structural elements.Building behaviour in this species is predominantly released by chemical stimuli like the building pheromone of the queen, the 'cement' pheromone and the trail pheromone (Bruinsma, unpublished). In view of the fact that the active space of the latter two pheromones directly depends on the number abd distribution of workers, it would appear, then, that the building latency time is inversely related to the workers group size. Grassé, (1959) has described such a density dependent effect on building activity in Cubitermes.The orientation required by building workers is mediated by trail- and 'cement' pheromone (directional orientation) and in the appropriate situation also by the building pheromone emanating from the queen (providing distance orientation). Other authors have documented examples of chemical orientation among termites. Leuthold (1975) has reviewed a body of evidence which shows that termites to a great extent rely on odour trail orientation. Stuart (1967) discovered that Zootermopsis is recruited to building sites by chemical trails. Grassé, (1959), Wilson (1971) and Deneubourg (1977) indicated the possibility of odours emanating from construction sites, orienting nearby motivated workers to such sites. This study furnishes convincing authentication of a pheromone emanating from a building site and confirms its rôle in worker orientation. Soil transporting workers arriving at a building site, e.g. located along a trail or in a deposition zone around the queen, attain a stable orientation with respect to that site prior to and during cementing their load. This response is probably to be due to the perception of a local stimulus, or stimulus complex. Such a mechanism of orientation is named telotaxis (Schöne, 1973), and implies as already emphasized by Fraenkel and Gunn (1961), simultaneous perception and evaluation of several stimuli.The results obtained with physical objects (small spheres) are in accordance with those of Stuart (1967) who demonstrated that surface irregularities release building behaviour in Nasutitermes. In respect of the ability of M . subhyalinus to perceive spatial relations between the discussed stimuli, it is of interest to mention a mechanism of orientation which has been described by Forel as: "By topochemical I mean a sense of smell which informs the ant as to the topography of the places surrounding it by means of chemical emanations which give an odour to objects" (Forel, 1928; cit. by Wilson, 1971, p252). To date such a mechanism integrating olfactory and mechanical information has been only demonstrated in honey bees (Martin, 1965) and the termites referred to in this study.Grassé, (1959, 1967) described in detail building behaviour in M . bellicosus , M . mülleri and Cubitermes sp. According to this author, it is the product of work previously accomplished, which constitutes the social stimulus for the workers to perform additional work (the concept of 'stigmergy'). In summary, two stages are distinguished: 1) A phase of 'unco-ordination' during which the workers first explore the container they are placed in, and after a certain time lapse start depositing soil pellets anywhere in the arena. When at some place the deposited material reaches a 'critical density' that is when several soil pellets are stuck together, this incipient structure proves to be very attractive to the workers compared to single pellets. 2) Subsequently the phase of 'co-ordination' is started during which workers transform the incipient structures into pillars, which, when a neighbouring one is within a critical distance, are combined to form arches. The concept of 'stigmergy' can be very well viewed in terms of the mechanism treated in the present study, except the observation that, initially, building is random. This observation is at variance with that of Stuart (1969), and the finding in the current study that workers employ the edge of a pheromone trail as a zone to co-ordinate soil depositions.Stuart (1967, 1969, and 1972) concludes that the behavioural basis of building is a response to a 'low level excitatory' stimulus, like air movement, odour, light, temperature etc., deviating from the normal nest environment. The subsequent building activity gradually eliminates the causal stimulus, and when no more environmental stimuli are forthcoming, building will stop. In conclusion, the immediate function of building is a homeostatic one. Since termites like most other social insects control the environment within the nest by actively maintaining several steady states, based on behavioural and physiological regulation (this phenomenon has been named 'social homeostasis' by Emerson, 1956), it is important to know whether the building mechanism proposed in this study is compatible with homeostatic regulation. At present it is only possible to indicate that there are several negative feedback mechanisms operating during building activity. At first, the ephemeral activity of both the trail- and the 'cement' pheromone is likely to modify the number of workers recruited to building sites. Secondly, it could be shown that major and minor workers during subsequent building runs loose between 20 - 40% of their fresh weight. In case workers are not allowed to compensate this loss by drinking at the water supply, they invariably stop building (Bruinsma, unpublished).The fact that pheromones, together with structural signals, are involved in the initiation and co-ordination of building behaviour in termites constitutes a plausible mechanism which accounts for most aspects of nest building behaviour in M . subhyalinus . The findings presented in this study may serve a useful purpose, increasing the understanding of the way in which termites perform such remarkable engineering feats as the construction of their impressive nest mounds.</TT
Evidence basis for antimalarial policy change in Sierra Leone: five in vivo efficacy studies of chloroquine, sulphadoxine-pyrimethamine and amodiaquine
No full textOBJECTIVES: To provide nationally relevant information on the antimalarial efficacy of chloroquine (CQ), sulphadoxine-pyrimethamine (SP) and amodiaquine (AQ) in Sierra Leone, with a view to updating antimalarial policy in the country. METHODS: Between October 2002 and May 2003, standard WHO methodology for in vivo efficacy assessment was used in five sites to study the therapeutic response of 6-59 months old uncomplicated Plasmodium falciparum malaria cases treated with CQ (n = 247), SP (n = 353) or AQ (n = 434). Follow-up was of 28 days, with polymerase chain reaction genotyping to distinguish late recrudescences from re-infections. RESULTS: Overall 85.3% of patients reached an analysable endpoint. CQ failure proportions were very high, ranging from 39.5% (95% CI: 25.0-55.6) in Kabala to 78.8% (65.3-88.9) in Kailahun. Early failures under CQ were frequent. SP efficacy was also disappointing, with failure from 23.2% (13.9-34.9) in Kabala to 46.1% (35.4-57.0) in Kailahun. AQ resistance was more moderate, ranging from 5.4% (1.8-12.1) in Makeni to 29.8% (20.3-40.8) in Kailahun, with almost no early failures. AQ also provided more rapid fever and parasite clearance. CONCLUSION: In a consensus meeting organized by the Ministry of Health and Sanitation, and based on these findings, artesunate (AS) + AQ and artemether-lumefantrine (Coartemtrade mark) were identified as the only options to rapidly replace CQ. The choice fell on AS + AQ because of expected high efficacy, lower cost in a blister presentation, and the absence of safety data on artemether-lumefantrine in pregnancy. Donor support is required to support this policy change. Throughout Africa, as SP resistance increases, these two regimens are probably the only options available while newer combinations are developed. Efficacy studies should focus on testing AQ and AS + AQ
